Posted by: "Rob Danielson"
> At 1:43 PM -0400 8/18/06, Walter Knapp wrote:
> <snip>
>
>>> ...have you tried the vibration suppression pads under the
>>>tripods. These pads are used in astronomy to isolate the tripod from
>>>ground vibrations which are everywhere. They certainly make a difference
>>>in astronomy.
>
>
> Yes, a "rigid" connection to the ground can transmit local vibrations
> on certain types of ground. I've experimented with several types of
> rig suspension to deal with different sources of vibration. With my
> garden tractor battery, 30 lb quadpack and hiking in, I only take my
> 8' tripod when I suspect there will be no suitable trees. I most
> often suspend the main weight of the four mic rig with several types
> of rope and bungee cords between 2-4 trees. I adjust rope tensions
> and dampen it with guy lines until I can "thump" the tree trunks and
> not produce resonance I can hear through the headphones. When it
> comes to suppressing transients, the suspension around the mic seems
> to be a significantly greater factor. A tree suspension usually
> performs better in windy conditions than my fixed tripod.
I'd really be suspecting that rope and bungee cord system. If its low
frequency then it's long spans that are producing it.
If your tree suspension is working better than your tripod then you
probably need to upgrade the tripod. If you are not doing so, try
hanging that battery on the tripod to weight it.
> Interesting suggestion about the tripod pads. Some claim, "Near 100%
> vibration elimination." Have you tried the pads?
The Celestron pads, but only for astrophotography. They do damp out
vibrations, not just those coming from the ground but somewhat those
originating in the tripod. Please note my astrophotography tripod weighs
70lbs to start with, so it's a different world. (Think about how you
would take photos with a 2000mm telephoto and you'll have the equivalent
of one of my scopes)
>>>I'd think the foam hanger would create new noises, particularly against
>>>elastic banding
>
>
> I was thinking of attaching the bands to a small, rectangular piece
> of sheet plastic and then gluing a foam block with a hole cut out
> onto the plastic so there's no direct contact between the bands and
> the foam. I use spongy foam for quickie dampening needs quite often.
> Rob D.
You can but try. One thing you don't want is any way those bands can
slide along something as they expand and contract under load.
Seems like the hard way to go about it when clips are readily available.
Though I'll admit I've kind of balked at machining up my own clips, a
lot of fiddly work there.
Walt
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